Field of the Invention
The present invention relates to a toner that is used in, for example, electrophotographic methods, electrostatic recording methods, and magnetic recording methods.
Description of the Related Art
Image-forming apparatuses that use electrophotographic methods, e.g., copiers, printers, and so forth, have in recent years been subjected to increasing diversification with regard to their intended applications and their use environment, and along with this greater energy-saving capabilities are being required. As a consequence, higher speeds, higher image quality, and smaller sizes are being required and the apparatus process speed is continually increasing.
However, increases in the process speed cause the appearance of a problem known as a poor paper back end rubbing performance, which is a fixing defect that is produced—particularly when the fixing unit has not been fully warmed up during initial image output—in the absence of a complete heat transmission from the fixing unit to the media to the very last.
Viewed from the standpoint of using the toner to improve upon the poor paper back end rubbing performance, toner having an enhanced low-temperature fixability is considered first. Means for achieving this includes, for example, modifying the binder resin and modifying crystalline substances such as the wax.
Focusing here on the crystalline substance, e.g., the wax, it is generally known that the fixing performance can be enhanced by lowering the viscosity upon melting by using large amounts of the crystalline substance. However, a problem has been that the durability and/or storability readily deteriorate when a crystalline substance is used in large amounts, and these have thus resided in a trade-off relationship.
With regard to methods for enhancing the fixing performance, Japanese Patent Application Laid-open No. 2011-145587 discloses a toner that has an excellent low-temperature fixability achieved by regulating the area ratio between a crystalline polyester and a wax.
In addition, Japanese Patent Application Laid-open No. 2008-33057 discloses that the low-temperature fixability is enhanced by controlling the area ratio and state of contact between a crystalline polyester and a release agent. Japanese Patent Application Laid-open No. 2006-84674 discloses that the fixing performance is improved by regulating the particle size distribution and size of wax particles.